AnswerPool

Busiest Filers API: Rank filers by filing volume over any window up to five years — SEC EDGAR

Rank filers by filing volume over any window up to five years, optionally per form — serial Form D issuers, heaviest 8-K disclosers, most active registrants — from our historical index in one call.

$0.02 per call — pay with prepaid card credits (Authorization: Bearer ck_live_…, packs from $1) or with USDC over x402: call it, get 402 with the price, retry signed. Failed calls are never charged.

How do you call it?

GET /v1/sec/filings/top — product id sec_busiest_filers. Over MCP, call answerpool_get with product_id=sec_busiest_filers.

curl "https://answerpool.io/v1/sec/filings/top?form=D&days=90"

# with a prepaid credit key
curl -H "Authorization: Bearer ck_live_..." "https://answerpool.io/v1/sec/filings/top?form=D&days=90"

Live call: https://answerpool.io/v1/sec/filings/top?form=D&days=90 · JSON sample: /v1/samples/sec_busiest_filers

What does the answer look like?

A representative response, the same static sample served at /v1/samples/sec_busiest_filers.

as_of2026-08-31T16:30:00Z
index_from2021-07-01
index_to2026-08-28
window_days90
formD
refresh_after2026-09-17T11:15:00.000Z

filers

cikcompanyfilings
0002150620Upfront Secondary II-C, L.P.3
The same sample as raw JSON
{
 "as_of": "2026-08-31T16:30:00Z",
 "index_from": "2021-07-01",
 "index_to": "2026-08-28",
 "window_days": 90,
 "form": "D",
 "filers": [
  {
   "cik": "0002150620",
   "company": "Upfront Secondary II-C, L.P.",
   "filings": 3
  }
 ],
 "refresh_after": "2026-09-17T11:15:00.000Z"
}

How fresh is it, and where does the data come from?

The fastest source behind this answer can change every 15 minutes, so every response carries a refresh_after timestamp — right now it would be 2026-09-17T11:15:00.000Z. Schedule the next call on that value rather than on a guess.

Method version 0.1.0 · serving cache 1 day · every response carries a result_id you can resolve at /v1/provenance.

When should you use it?

Ranked market questions by activity.

What you skip building

When should you not use it?

Salience-ranked events — the digest and screens rank by signal, not volume.

Where else can you find this?